1. Field of the Invention
This invention pertains to the field of catalytic compositions and methods for preparation and use thereof. More particularly, this invention pertains to a novel crystalline alumino-silicate zeolite catalyst and to a method of preparing such catalyst.
2. Description of the Prior Art
One of the recent major advances in catalyst technology was the discovery that catalytic compositions possessing both high activity and selectivity as well as superior attrition resistance in hydrocarbon conversion processing could be obtained by dispersing a crystalline aluminosilicate zeolite in an inorganic oxide matrix. Such compositions have been described, e.g., in U.S. Pat. Nos. 3,140,249 and 3,140,253 of C. J. Plank and E. J. Rosinski. It has further been found that certain desirable properties of such catalysts, including stability and activity, could be improved by replacing the alkali metals contained in the zeolites with other metals, particularly those of the rare earth group, and also by various pretempering treatments, e.g., steaming and dry thermal calcining.